Happy equilux! Spring arrives earlier than you thought

IT is another week until the clocks go forward for the start of British Summer Time, but the days around this weekend mark both the equinox and equilux - the astronomical signs that spring is officially here.

By The Newsroom

Published 17th Mar 2017, 14:29 BST

Updated 24th Mar 2017, 10:47 BST

Monday March 20 marks the equinox in the northern hemisphere, the point at which the length of day and night are “roughly equal”. It is considered the dividing point between winter and spring.

At this point, the sun appears as a disk in the sky, and the top half rises above the horizon before the centre. As well as this, sunlight is refracted by the Earth’s atmosphere.

But the equilux - the point at which day and night are exactly equal - occurs a few days earlier.

The timing depends on your location, but in Britain it occurs today, Friday, March 17.

Equinox is Latin for aequus (equal) and nox (night) meaning, roughly, “equal night”. The moment of the equinox is defined as the point at which the centre of the Sun’s disk crosses an imaginary line in the sky, the celestial equator.

Meanwhile, daylight saving time begins at 1am next Sunday, March 26.